Conventional flip chip quad flat nonleaded packages (“FC-QFN”) have reached a stage of maturity where numerous systems have been disclosed over the last few years. Generally, an integrated circuit (“IC”) chip is mounted on a leadframe and molded using epoxy molding compound (“EMC”). Interconnections are used to electrically connect the IC chip to the leadframe using solder joints, including gold stud bumps or solder bumps.
The leadframe consists of a paddle in the center and leads on the outside. The leads are divided into two sides. One side is an inner lead that electrically connects to the IC chip. The other side is an exposed terminal that electrically connects the package to other packages or the printed wiring board.
Inner leads are half-etched and encapsulated in order to prevent exposure to the outside. The leadframe thickness of half-etched inner lead design is required to be of a relatively high thickness in order to safely handle and process. Thus, high thickness leadframes are one barrier to reducing package size. In addition, thin leadframes are difficult to half-etch due to distortion or deformation of shape.
The leadframes, IC chip, and interconnects are all encapsulated in an epoxy. The epoxy encapsulates the entire FC-QFN, including the gap between the leadframe and the IC chip. However, the gap is very narrow and hard to fill without voids or delaminations. Therefore, a specially designed EMC or vacuum assisted molding machine is used, which increases assembly cost.
Thus, a need still remains for a thin leadframe structure with strong durability. In view of the ever-increasing need to save costs and improve efficiencies, it is more and more critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.